Lyocell blended yarn and preparation method thereof

Abstract

The invention relates to the technical field of lyocell fabrics, and discloses a lyocell blended yarn and a preparation method thereof.The lyocell blended yarn comprises modified lignocellulose fibers and cotton soft fibers, the modified lignocellulose fibers are formed by compositing the lignin fibers, polypropylene and carbon nanotubes, and the cotton soft fibers are formed by compositing the modified lignocellulose fibers, the polypropylene and the carbon nanotubes. The soft cotton fibers are cotton fibers grafted with glucose, and the soft cotton fibers wrap the outer layer of the modified wood fibers. The lyocell blended yarn is formed by blending the modified lignin fibers and the cotton soft fibers, and the carbon nanofibers are introduced into the modified lignin fibers, so that the mechanical strength of the fiber yarn can be effectively improved; the cotton soft fibers can be combined with the modified lignin fibers combined with polypropylene in a high-strength mode through grafted glucose, and the mechanical strength performance of the blended yarn is further optimized.

Description

Technical Field

[0001] The invention relates to the technical field of lyocell fabrics, and in particular to a lyocell blended yarn and a preparation method thereof. Background Art

[0002] Lyocell is a regenerated cellulose fiber made from wood cellulose. It has the properties of natural fiber cotton, such as smooth and comfortable texture and good air permeability, and has the advantage of less environmental pollution in the production process that traditional viscose fibers do not have. Lyocell fiber uses pulp formed by crushing renewable bamboo and wood as raw materials. It is directly dissolved by solvent and converted into fiber through spinning process. The recovery rate of the solvent used can be as high as 99.7%, and the process is energy-saving and environmentally friendly.

[0003] In order to further improve the comprehensive performance of Lyocell, technical means for improving or blending Lyocell fibers have been proposed. For example, the patent with publication number CN113897714A provides a Lyocell / cotton fiber blended yarn and a preparation method thereof. By blending cotton fiber and Lyocell fiber, and treating the cotton fiber with helium plasma, and then introducing glycidyl methacrylate for reaction modification, the oxidation and strength reduction problems of the fiber yarn under light can be effectively alleviated, and the mechanical strength stability of the fabric made of cotton fiber and Lyocell fiber can be improved.

[0004] However, in addition to the performance problems solved by the existing lyocell blended fibers, lyocell fibers also have the disadvantages of being easy to wrinkle, easy to snag and have holes, and poor wear resistance. When in use, they are easily damaged by friction during use and cleaning, which shortens the service life of the lyocell fibers. Therefore, there is an urgent need for a lyocell fiber with stronger mechanical tolerance. Summary of the invention

[0005] The technical problems to be solved by the present invention are:

[0006] As a natural plant fiber with good comfort and environmentally friendly production process, lyocell has outstanding performance characteristics, but it also has defects in some performance aspects. At present, the main ways to improve the performance of lyocell fiber include modifying the raw materials of lyocell fiber and blending lyocell fiber with other fiber materials. However, it is difficult for existing modified lyocell fiber or lyocell blended fiber to solve the problem of poor mechanical tolerance on the basis of meeting the requirements of comfort, breathability, energy saving and environmental protection.

[0007] The technical solution adopted by the present invention is:

[0008] The invention provides a lyocell blended yarn comprising modified lignin fiber and cotton fiber, wherein the modified lignin cellulose is composited with lignin fiber, polypropylene and carbon nanotubes, the cotton fiber is cotton fiber grafted with glucose, and the cotton fiber is wrapped around the outer layer of the modified lignin fiber.

[0009] Preferably, the method for preparing the soft cotton fiber comprises the following steps:

[0010] Take natural cotton fiber, place it in a dispersion solvent, add D-pyranose glucose, heat and stir, then take out the cotton fiber, heat and dry it to obtain the soft cotton fiber.

[0011] Preferably, the D-pyranose glucose is 0.5-1.25 wt % of the natural cotton fiber by mass.

[0012] Preferably, the heating temperature during heating and stirring is 60-75°C, and the heating temperature during heating and drying is 80-90°C.

[0013] Preferably, the method for preparing the modified lignin fiber comprises the following steps:

[0014] A1 purifies lignin, then mixes it with polypropylene chips, adds deionized water, and disperses it by ultrasonication to obtain lignin homogenate;

[0015] A2: adding a swelling agent to the lignin homogenate and soaking for 3-10 hours; then adding carbon nanofibers, ultrasonically dispersing, placing in a vacuum and filtering to obtain the modified lignin fiber

[0016] Preferably, in step A1, the mass ratio of the purified lignin to the polypropylene chips is 10-30:0.5-5.

[0017] Preferably, in step A1, the amount of deionized water used is 2.5-5 times the total volume of lignin and polypropylene chips.

[0018] Preferably, in step A1, the specific steps of purification treatment are:

[0019] The lignin is soaked in an acid solution, taken out and dried; then soaked in an alkali solution, taken out and dried; finally, it is repeatedly rinsed and dried with deionized water to obtain the purified lignin.

[0020] The present invention also provides a method for preparing the above-mentioned lyocell blended yarn, comprising the following steps:

[0021] Firstly, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into silk to obtain lignin monofilament; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn.

[0022] Preferably, the ratio of the thickness of the outer cotton fiber to the diameter of the inner core lignin monofilament is 0.2-0.8:1-1.5.

[0023] The beneficial effects of the present invention are as follows:

[0024] The lyocell blended yarn of the present invention is formed by blending modified lignin fiber and cotton fiber. In particular, the modified lignin fiber is swelled by introducing polypropylene, and combined with extremely strong carbon nanofibers, the mechanical strength of the fiber yarn can be effectively improved; the cotton fiber can be highly strongly combined with the modified lignin fiber through grafted glucose, further optimizing the mechanical strength performance of the blended yarn. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0026] The invention provides a lyocell blended yarn and a preparation method thereof. The lyocell blended yarn comprises modified lignin fiber and cotton soft fiber, and is prepared by blending the modified lignin fiber and the cotton soft fiber.

[0027] In the present invention, the modified lignin fiber is a composite fiber obtained by combining and modifying lignin fiber with a substance such as polypropylene, and the preparation method thereof comprises the following steps:

[0028] (1) soaking the lignin in a dilute hydrochloric acid solution, taking it out and drying it; soaking it in a sodium hydroxide solution, taking it out and drying it; finally, repeatedly rinsing and drying it with deionized water to obtain the lignin to be treated;

[0029] (2) mixing lignin and polypropylene chips in a mass ratio of 10-30:0.5-5, adding to 2.5-5 times the volume of deionized water, and ultrasonically dispersing to obtain a lignin homogenate;

[0030] (3) adding a swelling agent to the lignin slurry and soaking for 3-10 hours; then adding carbon nanofibers, ultrasonically dispersing, placing in a vacuum and filtering to obtain modified lignin fibers.

[0031] In the present invention, the method for preparing the above-mentioned soft cotton fiber comprises the following steps:

[0032] The natural cotton fiber is soaked in a dispersion solvent, and D-pyranose with a mass fraction of about 0.5-1.25% is added, heated to 60-75°C, stirred for 2.25-3h, and then the cotton fiber is taken out and further heated to about 80-90°C for drying to obtain soft cotton fiber.

[0033] In the present invention, the cotton soft fiber can be highly strongly combined with the modified lignin fiber through the grafted glucose, so that the blended yarn has higher mechanical strength. In addition, the modified lignin fiber can give full play to the excellent properties of cotton fiber such as skin-friendly and antibacterial when wrapped with the cotton soft fiber, so that the blended yarn has higher applicability.

[0034] In the present invention, the preparation method of the above-mentioned lyocell blended yarn is as follows:

[0035] Firstly, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into silk to obtain lignin monofilament; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn.

[0036] In the present invention, the ratio of the thickness of the outer cotton fiber to the diameter of the inner core lignin monofilament is 0.2-0.8:1-1.5.

[0037] Example 1

[0038] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0039] Step 2: Take 25 parts by mass of purified lignin and 2.2 parts by mass of polypropylene chips respectively, add 3 times the volume of deionized water of the total volume of lignin and polypropylene chips, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir well and soak for 6.25 hours; finally, add 15 parts by mass of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0040] Step 3: Take natural cotton fiber and soak it in acetic acid, add 1.05% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0041] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated, and the modified lignin fiber is spun into a lignin monofilament of about 0.85 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 22.3% of the fineness of the lyocell blended yarn.

[0042] Example 2

[0043] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0044] Step 2: Take 30 parts by mass of purified lignin and 1 part by mass of polypropylene slices respectively, add 3.5 times the volume of deionized water of the total volume of lignin and polypropylene slices, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir well and soak for 6.25 hours; finally, add 15 parts by mass of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0045] Step 3: Take natural cotton fiber and soak it in acetic acid, add 1.05% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0046] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into a lignin monofilament of about 0.90 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 22.3% of the fineness of the lyocell blended yarn.

[0047] Example 3

[0048] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0049] Step 2: Take 12 parts by mass of purified lignin and 4.7 parts by mass of polypropylene chips respectively, add 3 times the volume of deionized water of the total volume of lignin and polypropylene chips, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir well and soak for 6.25 hours; finally, add 15 parts by mass of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0050] Step 3: Take natural cotton fiber and soak it in acetic acid, add 1.05% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0051] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into a lignin monofilament of about 0.88 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 22.3% of the fineness of the lyocell blended yarn.

[0052] Example 4

[0053] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0054] Step 2: Take 25 parts by mass of purified lignin and 2.2 parts by mass of polypropylene slices respectively, add 3 times the volume of deionized water of the total volume of lignin and polypropylene slices, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir well and soak for 6.25 hours; finally, add 5 parts by mass of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0055] Step 3: Take natural cotton fiber and soak it in acetic acid, add 1.05% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0056] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into a lignin monofilament of about 0.84 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 22.3% of the fineness of the lyocell blended yarn.

[0057] Example 5

[0058] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0059] Step 2: Take 25 parts by weight of purified lignin and 2.2 parts by weight of polypropylene chips respectively, add 3 times the volume of deionized water of the total volume of lignin and polypropylene chips, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by weight of benzoyl peroxide, stir well and soak for 6.25 hours; finally, add 20 parts by weight of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fibers.

[0060] Step 3: Take natural cotton fiber and soak it in acetic acid, add 1.05% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0061] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into a lignin monofilament of about 0.91 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 22.3% of the fineness of the lyocell blended yarn.

[0062] Example 6

[0063] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0064] Step 2: Take 25 parts by mass of purified lignin and 2.2 parts by mass of polypropylene chips respectively, add 3 times the volume of deionized water of the total volume of lignin and polypropylene chips, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir well and soak for 6.25 hours; finally, add 15 parts by mass of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0065] Step 3: Take natural cotton fiber and soak it in acetic acid, add 0.62% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0066] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into a lignin monofilament of about 0.86 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 22.3% of the fineness of the lyocell blended yarn.

[0067] Example 7

[0068] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0069] Step 2: Take 25 parts by mass of purified lignin and 2.2 parts by mass of polypropylene chips respectively, add 3 times the volume of deionized water of the total volume of lignin and polypropylene chips, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir well and soak for 6.25 hours; finally, add 15 parts by mass of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0070] Step 3: Take natural cotton fiber and soak it in acetic acid, add 1.22% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0071] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into a lignin monofilament of about 0.88 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 22.3% of the fineness of the lyocell blended yarn.

[0072] Example 8

[0073] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0074] Step 2: Take 25 parts by mass of purified lignin and 2.2 parts by mass of polypropylene chips respectively, add 3 times the volume of deionized water of the total volume of lignin and polypropylene chips, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir well and soak for 6.25 hours; finally, add 15 parts by mass of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0075] Step 3: Take natural cotton fiber and soak it in acetic acid, add 1.05% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0076] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into a lignin monofilament of about 0.89 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 35.5% of the fineness of the lyocell blended yarn.

[0077] Comparative Example 1

[0078] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0079] Step 2: Take 25 parts by mass of purified lignin and 2.2 parts by mass of polypropylene chips respectively, add 3 times the volume of deionized water of the total volume of lignin and polypropylene chips, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir well and soak for 6.25 hours; finally, add 15 parts by mass of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0080] Step 3: Combing and separating the modified lignin fibers, and spinning the modified lignin fibers into lyocell yarns of about 0.91 dtex.

[0081] Comparative Example 2

[0082] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0083] Step 2: Take 25 parts by mass of purified lignin, add 3 times the volume of deionized water of lignin, and ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir and soak for 6.25 hours; finally, add 15 parts by mass of carbon nanofibers, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0084] Step 3: Take natural cotton fiber and soak it in acetic acid, add 1.05% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0085] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into a lignin monofilament of about 0.83 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 25.1% of the fineness of the lyocell blended yarn.

[0086] Comparative Example 3

[0087] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0088] Step 2: Take 25 parts by mass of purified lignin and 2.2 parts by mass of polypropylene chips respectively, add 3 times the volume of deionized water of the total volume of lignin and polypropylene chips, ultrasonically disperse for 30 minutes to obtain lignin homogenate; then add 3 parts by mass of benzoyl peroxide, stir and soak for 6.25 hours, ultrasonically disperse for 2.5 hours, and vacuum filter to obtain modified lignin fiber.

[0089] Step 3: Take natural cotton fiber and soak it in acetic acid, add 1.05% D-pyranose by mass, heat it to 70±2°C, stir it at 650rpm for 2.5h, then take out the cotton fiber, heat it to 83±2°C until it is dried to obtain soft cotton fiber.

[0090] Step 4: First, the modified lignin fiber and the cotton fiber are combed and separated, and the modified lignin fiber is spun into a lignin monofilament of about 0.85 dtex; then, the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn, and the thickness of the cotton fiber is about 22.3% of the fineness of the lyocell blended yarn.

[0091] Comparative Example 4

[0092] Step 1: soak the lignin in 18% dilute hydrochloric acid solution, take it out and dry it; soak it in 20% sodium hydroxide solution, take it out and dry it; finally rinse it repeatedly with deionized water and dry it twice to obtain purified lignin.

[0093] Step 2: Take 25 parts by weight of purified lignin, add deionized water 3 times the volume of lignin, and ultrasonically disperse for 30 minutes to obtain a lignin slurry, vacuum filter it, and obtain lignin fiber; comb the lignin fiber to separate it into filaments, and weave it into lignin yarn.

[0094] <Test example>

[0095] Samples: Examples 1-8, Comparative Examples 1-4

[0096] The lyocell yarns prepared in Examples 1-8 and Comparative Examples 1-4 were taken as samples, and the breaking strength and other properties of the samples were tested using a yarn abrasion tester. The results are summarized in Table 1 below:

[0097] Table 1 Test results of fracture strength and other properties of different samples

[0098] Comparison Items Breaking strength (dtex) Elongation(%) Example 1 8.65 33 Example 2 8.27 36 Example 3 8.32 32 Example 4 7.15 33 Example 5 8.03 32 Example 6 6.93 34 Example 7 7.80 35 Example 8 8.96 31 Comparative Example 1 4.00 29 Comparative Example 2 4.01 25 Comparative Example 3 3.93 26 Comparative Example 4 2.16 18

[0099] As can be seen from Table 1 above, the breaking strength and elongation of the lyocell yarn samples prepared in Examples 1 to 8 are generally higher than those in Comparative Examples 1 to 4, which indicates that the lyocell yarns have stronger mechanical strength. In other words, the improved method of lyocell fiber proposed in the present invention can improve the mechanical tolerance of lyocell blended yarns.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A lyocell blended yarn, characterized in that: The modified wood cellulose comprises modified lignin fiber and cotton fiber. The modified wood cellulose is composited with lignin fiber, polypropylene and carbon nanotubes. The cotton fiber is cotton fiber grafted with glucose, and the cotton fiber is wrapped around the outer layer of the modified wood fiber.

2. The lyocell blended yarn according to claim 1, characterized in that The method for preparing the soft cotton fiber comprises the following steps: Natural cotton fibers are placed in a dispersion solvent, D-pyranose is added, and the mixture is heated and stirred. The cotton fibers are then taken out and heated and dried to obtain the soft cotton fibers.

3. The lyocell blended yarn according to claim 2, characterized in that: Calculated by mass, the D-pyranose glucose accounts for 0.5-1.25 wt% of the natural cotton fiber.

4. The lyocell blended yarn according to claim 2, characterized in that: The heating temperature during heating and stirring is 60-75°C, and the heating temperature during heating and drying is 80-90°C.

5. The lyocell blended yarn according to claim 1, characterized in that: The preparation method of the modified lignin fiber comprises the following steps: A1 purifies lignin, then mixes it with polypropylene chips, adds deionized water, and disperses it by ultrasonication to obtain a lignin homogenate; A2: adding a swelling agent to the lignin homogenate and soaking for 3-10 hours; then adding carbon nanofibers, ultrasonically dispersing, placing in a vacuum and filtering to obtain the modified lignin fibers.

6. The lyocell blended yarn according to claim 5, characterized in that: In step A1, the mass ratio of the purified lignin to the polypropylene chips is 10-30:0.5-5.

7. The lyocell blended yarn according to claim 5, characterized in that: In step A1, the amount of deionized water used is 2.5-5 times the total volume of the lignin and polypropylene chips.

8. The lyocell blended yarn according to claim 5, characterized in that: In step A1, the specific steps of the purification process are: The lignin is soaked in an acid solution, taken out and dried; then soaked in an alkaline solution, taken out and dried; finally, repeatedly rinsed with deionized water and dried to obtain purified lignin.

9. A method for preparing the lyocell blended yarn according to any one of claims 1 to 8, characterized in that: The steps include: First, the modified lignin fiber and the cotton fiber are combed and separated respectively, and the modified lignin fiber is spun into silk to obtain lignin monofilament; then the cotton fiber is sprayed onto the outer layer of the spirally rotating lignin monofilament to form a spirally woven lyocell blended yarn.

10. The method for preparing lyocell blended yarn according to claim 9, wherein: The ratio of the thickness of the outer cotton fiber to the diameter of the inner core lignin monofilament is 0.2-0.8:1-1.5.